Sand Binder Jetting 3D Printers
Binder Jetting is an additive manufacturing process in which a binding agent is deposited to join powder particles. Layers of material are then bonded to form the object. In Sand Binder Jetting (SBJ) the powder is bound using a polymer binding agent. SBJ is often used in modeling and in the creation of sand cast molds for manufacturing.
For full color models, objects are fabricated using a plaster-based or PMMA powder along with a liquid binding agent. The printhead first jets the binding agent, while a secondary printhead jets in color, allowing full color models to be printed.
“The binder jetting process uses two materials; a powder based material and a binder. The binder acts as an adhesive between powder layers. The binder is usually in liquid form and the build material in powder form. A print head moves horizontally along the x and y axes of the machine and deposits alternating layers of the build material and the binding material. After each layer, the object being printed is lowered on its build platform.
Due to the method of binding, the material characteristics are not always suitable for structural parts and despite the relative speed of printing, additional post processing (see below) can add significant time to the overall process.
As with other powder based manufacturing methods, the object being printed is self-supported within the powder bed and is removed from the unbound powder once completed. The technology is often referred to as 3DP technology and is copyrighted under this name.”